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Number of farrowing records by breed and parity

 
Parity
Breed No. of sows 1 2 3
Yorkshire 1,075 888 642 237
Landrace 1,032 836 564 257



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Descriptive statistics of the traits studied by breed

 
Yorkshire
Landrace
Trait Trait abbreviation, unit n Mean (SD) n Mean (SD)
Body weight at farrowing BWF, kg 1,758 228.3 (24.0) 1,647 223.5 (23.5)
Back fat at farrowing BFF, mm 1,759 22.4 (4.7) 1,652 22.4 (4.9)
Loin depth at farrowing LDF, mm 1,759 64.0 (7.0) 1,652 65.0 (6.9)
Body weight loss BWL, kg 1,681 11.9 (13.6) 1,580 7.3 (13.5)
Back fat loss BFL, mm 1,688 2.5 (3.9) 1,590 2.4 (3.7)
Loin depth loss LDL, mm 1,686 2.3 (6.9) 1,590 2.6 (7.0)
Sow feed intake SFI, kg 1,767 103.0 (27.0) 1,657 93.8 (25.8)
Energy input EIP, MJ ME/d2 1,611 55.8 (16.4) 1,503 50.6 (14.7)
Litter weight gain LWG, kg 1,760 46.7 (13.01) 1,649 44.9 (12.6)
Energy output EOP, MJ ME/d2 1,760 34.3 (7.2) 1,649 33.7 (7.0)
Sow lactation efficiency SLE, % 1,611 67.2 (21.4) 1,503 73.0 (23.2)
Energy balance 1 EB1, MJ ME/d2 1,611 −11.8 (14.1) 1,516 −10.2 (13.8)
Energy balance 2 EB2, MJ ME/d2 1,681 −14.8 (10.9) 1,580 −17.1 (9.8)
Live born piglets LBP 1,767 13.0 (3.3) 1,657 12.0 (3.0)
Stillborn piglets SBP 1,767 1.6 (1.7) 1,657 1.4 (1.6)
Litter size at birth LSB 1,767 15.0 (3.7) 1,657 13.6 (3.3)
Litter size at weaning LSW 1,767 10.4 (2.5) 1,657 10.0 (2.4)



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Estimates of heritability (parity1, parity 2, and overall), permanent environment effects, and genetic correlations for the same trait measured in parities 1 and 2 in Yorkshire sows

 
Variance
Heritability (SE)
Trait1 Sow Permanent environment Phenotypic3 Overall Heritability (SE) Permanent environment effects (SE) Parity 1 Parity 2 Genetic correlation between parities 1 and 2 (SE)2
BWF 67.28 104.10 285.10 0.24 (0.05) 0.36 (0.04) 0.26 (0.07) 0.27 (0.09) 0.74 (0.13)
BFF 5.83 4.56 20.04 0.29 (0.06) 0.23 (0.05) 0.33 (0.08) 0.22 (0.08) 0.98 (0.11)
LDF 12.36 4.22 40.06 0.31 (0.05) 0.11 (0.05) 0.35 (0.08) 0.29 (0.09) 0.65 (0.16)
BWL 37.46 21.43 150.72 0.25 (0.05) 0.14 (0.05) 0.34 (0.08) 0.25 (0.08) 0.91 (0.10)
BFL 0.92 0.80 9.44 0.10 (0.04) 0.09 (0.05) 0.03 (0.05) 0.00 (0.00) NE
LDL 3.77 3.10 29.25 0.13 (0.04) 0.11 (0.05) 0.12 (0.06) 0.19 (0.09) 0.90 (0.30)
SFI 65.73 36.46 236.02 0.28 (0.05) 0.15 (0.05) 0.31 (0.08) 0.23 (0.08) 0.86 (0.16)
EIP 2.05 32.77 161.82 0.01 (0.03) 0.20 (0.05) 0.00 (0.00) 0.03 (0.07) NE
LWG 10.78 4.86 67.19 0.16 (0.04) 0.07 (0.05) 0.22 (0.08) 0.17 (0.08) 0.85 (0.17)
EOP 3.57 1.85 21.22 0.17 (0.05) 0.09 (0.05) 0.21 (0.08) 0.20 (0.09) 0.83 (0.18)
SLE 0.00 33.76 394.42 0.00 (0.00) 0.09 (0.03) 0.00 (0.00) 0.00 (0.00) NE
EB1 18.86 16.88 143.34 0.13 (0.04) 0.12 (0.05) 0.11 (0.07) 0.08 (0.08) NE
EB2 23.07 10.50 77.28 0.30 (0.05) 0.14 (0.05) 0.34 (0.08) 0.19 (0.08) 0.92 (0.16)
SRFI 49.79 30.15 193.38 0.26 (0.05) 0.16 (0.05) 0.22 (0.08) 0.19 (0.08) 0.87 (0.16)
LBP 0.58 0.87 9.24 0.06 (0.03) 0.09 (0.05) 0.06 (0.05) 0.15 (0.08) 0.70 (0.45)
SBP 0.35 0.20 2.99 0.12 (0.04) 0.07 (0.05) 0.17 (0.07) 0.09 (0.06) 0.88 (0.32)
LSB 1.48 1.85 13.49 0.11 (0.04) 0.14 (0.05) 0.04 (0.05) 0.25 (0.09) 0.86 (0.56)
LSW 0.23 0.66 5.21 0.04 (0.03) 0.13 (0.05) 0.00 (0.05) 0.12 (0.08) NE
1BWF = body weight at farrowing; BFF = back fat at farrowing; LDF = loin depth at farrowing; BWL = body weight loss; BFL = back fat loss; LDL = loin depth loss; SFI = total feed intake; EIP = energy input; LWG = litter weight gain; EOP = energy output; SLE = sow lactation efficiency; EB1 = energy balance 1; EB2 = energy balance 2; SRFI = sow residual feed intake; LBP = live-born piglets; SBP = stillborn piglets; LSB = litter size at birth; LSW = litter size at weaning.
2NE = convergence not attained, and hence, estimates could not be obtained.
3Phenotypic variance was calculated from ASReml analyses : σ2 error + σ2 sow + σ2 permanent environment.



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Estimates of heritability (parity1, parity 2, and overall), permanent environment effects, and genetic correlations for the same trait measured in parities 1 and 2 in Landrace sows

 
Variance
Heritability (SE)
Trait1 Sow Permanent environment Phenotypic3 Overall Heritability (SE) Permanent environment effects (SE) Parity 1 Parity 2 Genetic correlation between parities 1 and 2 (SE)2
BWF 53.84 68.72 256.43 0.21 (0.05) 0.27 (0.05) 0.34 (0.08) 0.10 (0.07) 0.81 (0.15)
BFF 8.59 4.11 22.84 0.38 (0.06) 0.18 (0.05) 0.47 (0.08) 0.16 (0.08) 0.77 (0.28)
LDF 9.57 3.27 39.50 0.24 (0.05) 0.08 (0.05) 0.20 (0.07) 0.19 (0.10) NE
BWL 44.02 0.00 135.59 0.32 (0.04) 0.00 (0.00) 0.41 (0.08) 0.42 (0.11) 0.84 (0.11)
BFL 1.53 0.50 9.71 0.16 (0.04) 0.05 (0.05) 0.07 (0.06) 0.20 (0.09) 0.88 (0.49)
LDL 3.62 1.02 29.28 0.12 (0.04) 0.03 (0.05) 0.07 (0.06) 0.20 (0.10) NE
SFI 76.70 16.76 206.26 0.37 (0.06) 0.08 (0.05) 0.33 (0.08) 0.19 (0.10) 0.93 (0.21)
EIP 16.57 12.06 153.32 0.11 (0.04) 0.08 (0.05) 0.00 (0.05) 0.22 (0.09) NE
LWG 6.83 0.66 38.57 0.18 (0.05) 0.02 (0.05) 0.12 (0.06) 0.20 (0.10) 0.80 (0.23)
EOP 2.35 1.13 13.44 0.17 (0.05) 0.08 (0.05) 0.10 (0.06) 0.17 (0.10) 0.85 (0.22)
SLE 23.58 12.85 437.11 0.05 (0.03) 0.03 (0.05) 0.00 (0.00) 0.16 (0.08) NE
EB1 32.70 0.00 140.39 0.23 (0.05) 0.00 (0.00) 0.26 (0.08) 0.25 (0.09) 0.65 (0.25)
EB2 22.60 4.35 61.65 0.36 (0.06) 0.07 (0.05) 0.45 (0.09) 0.21 (0.10) NE
SRFI 50.59 12.31 170.17 0.30 (0.06) 0.07 (0.05) 0.34 (0.08) 0.11 (0.08) 0.93 (0.16)
LBP 0.59 0.84 7.93 0.07 (0.04) 0.11 (0.05) 0.21 (0.07) 0.04 (0.07) 0.64 (0.48)
SBP 0.28 0.32 2.52 0.11 (0.04) 0.13 (0.05) 0.09 (0.06) 0.19 (0.10) 0.88 (0.32)
LSB 1.76 0.80 10.54 0.17 (0.05) 0.08 (0.05) 0.27 (0.07) 0.06 (0.07) 0.65 (0.35)
LSW 0.08 0.75 4.44 0.02 (0.03) 0.17 (0.05) 0.00 (0.00) 0.09 (0.07) NE
1BWF = body weight at farrowing; BFF = back fat at farrowing; LDF = loin depth at farrowing; BWL = body weight loss; BFL = back fat loss; LDL = loin depth loss; SFI = Total feed intake; EIP = energy input; LWG = litter weight gain; EOP = energy output; SLE = sow lactation efficiency; EB1 = energy balance 1; EB2 = energy balance 2; SRFI = sow residual feed intake; LBP = live-born piglets; SBP = stillborn piglets; LSB = litter size at birth; LSW = litter size at weaning.
2NE = convergence not attained, and hence, estimates could not be obtained.
3Phenotypic variance was calculated from ASReml analyses: σ2 error + σ2 sow + σ2 permanent environment.



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Estimates of genetic correlations between prefarrow, input, output, efficiency, and reproductive traits for Yorkshire (below diagonal) and Landrace sows (above diagonal)1

 
Traits2 BWF BFF LDF BWL BFL LDL SFI LWG EOP SLE EB1 EB2 SRFI LBP SBP LSB LSW
BWF 0.49 (0.13) 0.02 (0.17) 0.01 (0.16) −0.41 (0.18) −0.18 (0.21) 0.36 (0.15) 0.18 (0.18) 0.08 (0.19) 0.53 (0.23) 0.39 (0.14) 0.13 (0.17) 0.27 (0.16) 0.00 (0.22) −0.08 (0.17) −0.15 (0.17) NE
BFF 0.43 (0.13) 0.39 (0.13) −0.29 (0.09) −0.903 (0.08) −0.25 (0.20) −0.26 (0.12) 0.18 (0.13) 0.09 (0.13) −0.35 (0.36) 0.03 (0.16) 0.07 (0.13) −0.26 (0.12) −0.07 (0.18) −0.43 (0.17) −0.25 (0.16) −0.50 (0.66)
LDF 0.39 (0.14) 0.23 (0.14) −0.063 (0.15) −0.02 (0.18) −0.623 (0.17) −0.11 (0.15) −0.12 (0.18) −0.22 (0.18) −0.03 (0.28) 0.163 (0.16) 0.09 (0.15) −0.18 (0.15) 0.00 (0.21) −0.34 (0.17) −0.16 (0.17) −0.09 (0.36)
BWL −0.30 (0.18) −0.23 (0.15) −0.23 (0.14) 0.01 (0.18) 0.49 (0.16) −0.60 (0.09) 0.49 (0.16) 0.49 (0.17) −0.12 (0.25) −0.80 (0.07) −0.73 (0.08) 0.083(0.15) −0.16 (0.18) −0.28 (0.20) −0.21 (0.16) −0.08 (0.38)
BFL −0.66 (0.13) −0.65 (0.17) −0.44 (0.19) 0.51 (0.17) 0.31 (0.19) −0.63 (0.15) 0.39 (0.16) 0.53 (0.17) −0.54 (0.14) −0.90 (0.02) −0.23 (0.13) −0.51 (0.21) 0.17 (022) −0.11 (0.24) 0.12 (0.19) 0.03 (0.45)
LDL −0.37 (0.17) 0.11 (0.19) −0.69 (0.15) 0.60 (0.15) 0.47 (0.22) −0.11 (0.19) 0.39 (0.21) 0.29 (0.22) −0.36 (0.34) −0.42 (0.16) −0.31 (0.17) 0.14 (0.19) 0.42 (0.26) 0.00 (0.27) 0.33 (0.22) −0.53 (0.57)
SFI 0.50 (0.15) −0.09 (0.15) −0.08 (0.14) −0.70 (0.09) −0.52 (0.21) −0.35 (0.17) 0.31 (0.18) 0.23(0.18) −0.48 (0.20) 0.58 (0.10) 0.90 (0.04) 0.92 0.01) −0.01 (0.19) 0.38 (0.21) 0.08 (0.17) 0.40 (0.38)
LWG −0.05 (0.19) 0.04 (0.19) −0.45 (0.16) 0.24 (0.17) 0.42 (0.21) 0.52 (0.19) 0.12 (0.17) NE −0.27 (0.23) −0.40 (0.14) −0.20 (0.11) 0.283 (0.16) −0.02 (0.22) 0.14(0.24) 0.03 (0.20) 0.33 (0.45)
EOP −0.04 (0.19) 0.01(0.18) −0.41 (0.16) 0.29 (0.16) 0.53 (0.20) 0.57 (0.18) 0.06 (0.18) NE −0.27 (0.29) −0.43 (0.14) −0.39 (0.14) 0.23 (0.16) −0.12 (0.22) 0.13 (0.25) −0.08 (0.20) 0.59 (0.38)
SLE NE NE NE NE NE NE NE NE NE NE NE −0.70 (0.11) −0.38 (0.31) 0.10 (0.37) −0.31 (0.27) −0.11 (0.71)
EB1 0.71 (0.13) 0.48 (0.15) 0.45 (0.16) −0.91 (0.07) −0.88 (0.06) −0.67 (0.17) 0.92 (0.14) −0.33 (0.19) −0.43 (0.18) NE 0.73 (0.11) 0.35 (0.17) −0.11 (0.20) 0.12 (0.22) −0.09 (0.18) −0.11 (0.42)
EB2 0.35 (0.16) −0.03 (0.15) 0.18 (0.14) −0.74 (0.09) −0.75 (0.15) −0.60 (0.15) 0.85 (0.06) −0.52 (0.13) −0.56 (0.12) NE 0.85 (0.08) NE 0.14 (0.19) 0.23 (0.20) 0.19 (0.16) 0.06 (0.39)
SRFI 0.42 (0.15) −0.10 (0.15) −0.01 (0.14) −0.66 (0.11) −0.43 (0.24) −0.27 (0.18) 0.95 (0.01) 0.13 (0.18) −0.07 (0.18) NE 0.69 (0.19) NE −0.06 (0.21) 0.41 (0.21) 0.08 (0.17) 0.33 (0.49)
LBP −0.30 (0.24) −0.31 (0.23) −0.44 (0.22) −0.23 (0.22) −0.32 (0.33) −0.01 (0.27) −0.06 (0.24) 0.03 (0.28) −0.02 (0.28) NE 0.16 (0.28) −0.03 (0.22) −0.33 (0.23) 0.15 (0.27) NE 0.19 (0.55)
SBP −0.32 (0.19) −0.20 (0.19) −0.26 (0.18) 0.18 (0.18) 0.35 (0.25) 0.08 (0.23) −0.09 (0.19) 0.09 (0.22) 0.14 (0.21) NE −0.33 (0.21) −0.24 (0.19) −0.09 (0.20) −0.08 (0.29) 0.59 (0.18) 0.26 (0.64)
LSB −0.39 (0.20) −0.41 (0.20) −0.49 (0.17) −0.13 (0.19) −0.01 (0.29) 0.01 (0.24) −0.09 (0.20) 0.01 (0.24) −0.01 (0.24) NE −0.06 (0.24) −0.13 (0.20) −0.31 (0.21) NE 0.54 (0.18) 0.30 (0.62)
LSW 0.21 (0.31) −0.23 (0.29) −0.12 (0.29) 0.20 (0.26) 0.26 (0.40) 0.26 (0.32) −0.04 (0.27) 0.86 (0.21) 0.80 (0.16) NE −0.35 (0.30) −0.61 (0.18) −0.34 (0.24) −0.13 (0.43) 0.28 (0.36) 0.17 (0.37)
1SE are in parentheses. Bold genetic correlations differ from zero (P < 0.05). NE = Convergence not attained and hence estimates could not be obtained.
2BWF = body weight at farrowing; BFF = back fat at farrowing; LDF = loin depth at farrowing; BWL = body weight loss; BFL = back fat loss; LDL = loin depth loss; SFI = total feed intake; LWG = litter weight gain; EOP = energy output; SLE = sow lactation efficiency; EB1 = energy balance 1; EB2 = energy balance 2; SRFI = sow residual feed intake; LBP = live-born piglets; SBP = stillborn piglets; LSB = litter size at birth; LSW = litter size at weaning.
3Convergence attained using preadjusted traits.



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Estimates of genetic correlations between lactation traits in parity 1 and reproductive traits in parity 21

 
Parity 2 reproduction traits, Yorkshire
Parity 2 reproduction traits, Landrace
Parity 1 lactation traits LBP LSB LSW LBP LSB LSW
BWL −0.28 (0.32) −0.25 (0.22) −0.04 (0.30) −0.02 (0.50) −0.29 (0.40) 0.13 (0.35)
BFL −0.84 (0.47) −0.53 (0.39) −0.33 (0.63) −0.14 (0.34) −0.30 (0.38) 0.21 (0.54)
SFI 0.05 (0.27) −0.01 (0.23) −0.25 (0.28) 0.31 (0.53) 0.42 (0.43) 0.24 (0.36)
SRFI −0.09 (0.30) −0.22 (0.26) −0.16 (0.32) 0.48 (0.60) 0.48 (0.46) 0.29 (0.38)
EB1 0.55 (0.39) 0.30 (0.34) 0.06 (0.47) −0.40 (0.56) −0.11 (0.46) −0.36 (0.41)
EB2 0.34 (0.26) 0.35 (0.22) −0.13 (0.30) 0.29 (0.48) 0.29 (0.39) −0.11 (0.34)
1SE are in parentheses. Bold correlations differ from zero (P < 0.05). BWL = body weight loss; BFL = back fat loss; SFI = total feed intake; SRFI = sow residual feed intake; EB1 = energy balance 1; EB2 = energy balance 2; LBP = live-born piglets; LSB = litter size at birth; LSW = litter size at weaning.



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Estimates of genetic correlations between economically important traits and indicator traits in Yorkshire sows1

 
Parity 1 economically important traits
Parity 2 economically important traits
Indicator traits in parity 1 SFI SRFI LWG SFI SRFI LWG LSB
BWF 0.49 (0.19) 0.56 (0.20) −0.04 (0.24) 0.55 (0.22) 0.48 (0.22) −0.08 (0.30) 0.06 (0.24)
BFF −0.21 (0.19) −0.12 (0.21) −0.01 (0.22) 0.04 (0.23) 0.07 (0.23) 0.51 (0.24) 0.01 (0.22)
LDF −0.16 (0.19) −0.14 (0.20) −0.67 (0.17) 0.04 (0.23) −0.05 (0.22) −0.01 (0.27) −0.11 (0.22)
BWL −0.80 (0.11) −0.85 (0.09) 0.22 (0.21) −0.42 (0.20) −0.15 (0.22) 0.39 (0.24) −0.25 (0.22)
BFL −0.86 (0.53) −0.81 (0.52) 0.44 (0.36) −0.90 (0.75) −0.35 (0.49) 0.74 (0.41) −0.53 (0.39)
LDL −0.49 (0.25) −0.23 (0.30) 0.87 (0.32) −0.19 (0.32) −0.16 (0.33) 0.76 (0.51) −0.76 (0.35)
1SE are in parentheses. Bold correlations differ from zero (P < 0.05). BWF = body weight at farrowing; BFF = back fat at farrowing; LDF = loin depth at farrowing; BWL = body weight loss; BFL = back fat loss; LDL = loin depth loss; SFI = total feed intake; LWG = litter weight gain; SRFI = sow residual feed intake; LSB = litter size at birth.



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Estimates of genetic correlations between economically relevant traits and indicator traits in Landrace sows1

 
Parity 1 economically relevant traits
Parity 2 economically relevant traits2
Indicator traits in parity 1 SFI SRFI LWG SFI SRFI LWG LSB
BWF 0.43 (0.18) 0.41 (0.19) 0.56 (0.24) 0.46 (0.27) 0.14 (0.28) 0.20 (0.28) −0.46 (0.42)
BFF −0.23 (0.16) −0.29 (0.16) 0.42 (0.23) 0.16 (0.25) −0.60 (0.22) −0.22 (0.24) −0.36 (0.32)
LDF −0.01 (0.23) −0.24 (0.23) 0.07 (0.32) NE NE −0.36 (0.30) 0.28 (0.48)
BWL −0.74 (0.10) −0.75 (0.11) 0.38 (0.26) −0.86 (0.24) −0.73 (0.28) 0.07 (0.27) −0.29 (0.40)
BFL −0.66 (0.32) −0.28 (0.35) 0.88 (0.34) NE NE 0.91 (0.48) −0.30 (0.71)
LDL −0.04 (0.35) 0.33 (0.38) 0.47 (0.45) −0.69 (0.52) −0.29 (0.50) 0.12 (0.49) NE
1SE are in parentheses. Bold correlations differ from zero (P < 0.05). BWF = body weight at farrowing; BFF = back fat at farrowing; LDF = loin depth at farrowing; BWL = body weight loss; BFL = back fat loss; LDL = loin depth loss; SFI = total feed intake; LWG = litter weight gain; SRFI = sow residual feed intake; LSB = litter size at birth.
2NE = convergence not attained, and hence, estimates could not be obtained.